1. Field of the Invention
The present invention relates to an image pickup apparatus.
2. Description of the Related Art
In the field of the optical flow, it is necessary to obtain motion information of an object, but when a plurality of images are obtained at a high speed at the same exposure time, a large storage capacity and high-speed processing become required.
Accordingly, Japanese Patent No. 3643210 proposes a method for presenting a correlation image representing a time correlation between incident light and a reference signal by utilizing an image sensor configured to provide a reference signal to photoelectrically converted current and to time-integrate and output the modulated current. Japanese Domestic Publication No. 2009-522825 proposes a method for encoding by opening and closing a shutter at irregular time intervals in obtaining one image, and for decoding the obtained, coded image so as to remove blurs in the image. JP 2003-344901 proposes a method for modulating a light quantity using a spatial light modulator instead of an exposure controlling filter for the image pickup.
However, Japanese Patent No. 3643210 utilizes the special image sensor, and thus the production cost increases. In addition, since one photodiode needs a plurality of capacitors, one pixel becomes large and a high resolution becomes difficult. Neither Japanese Domestic Publication No. 2009-522825 nor Japanese Patent Laid-Open No. 2003-344901 addresses an acquisition of information of a variation with time of the object.